In prior art portable communication devices, the antenna and the portable communication device are matched for free space conditions. The matching between the portable communication device and the antenna deteriorates when a disturbing object, such as the human body, :s present near the antenna. This effect is known as the proximity effect. As a result of this effect, in the transmitting situation as well as in the receiving situation considerable signal losses may occur.
In European Patent 0 341 238, some ways to avoid the proximity effect are described. In column 2, lines 1-16, it is described that the antenna and the communication device are matched in the situation, that the antenna is "on" the body. This solution, has the drawback, that the performance in free space conditions is bad. Another solution described in EP 0 341 238 is to adaptively match the antenna and the communication device, in dependence on the situation. This solution has the drawback, that extra means are necessary, for measuring the quality of matching between the antenna and the communication device and changing the impedances of the communication device and/or antenna, when matching is bad. This makes that such a communication device complicated.